1. Field of the Invention
The present invention relates to a charging system and, more particularly, to a charging system for a portable electronic device.
2. Brief Description of Prior Developments
The use of battery operated portable electronic devices has been increasing, such as mobile telephones, PDAs, MP3 players, etc. Problems associated with the discharge of batteries in portable electronic devices has, thus, been increasing. Likewise, the need to recharge batteries of portable electronic devices while away from the home or office has increased. Battery charging trays which use induction for charging batteries in portable electronic devices are known in the art, such as devices offered for sale by Splashpower Ltd. and MobileWise Inc. However, these types of battery charging trays must be directly connected to an electrical outlet or main, and have a relatively large footprint. A tray can be difficult to carry, and not all portable electronic devices have the necessary circuitry or chips to use these types of induction trays. Another problem is a simple organization issue, such as neatly organizing a family of different products, in a compact manner, with a charging device.
FIG. 1 in the accompanying drawings shows a portable telephone 1 being charged by a contactless charging system, based upon electromagnetic induction, which is known to exist in the prior art. The portable telephone 1 includes a secondary side coil 2. The charging system comprises a charger 3 which includes a primary side coil 7. A user can set the portable telephone 1 on the housing of the charger 3 as shown in the figure. The charger 3 can charge a battery 8 in the portable telephone 1, such as when the portable telephone has not been used for a long time or when the remaining battery capacity of the battery in the portable telephone become small.
With the prior art charging system shown in FIG. 1, a spacing 5 is provided between the primary side coil 7 and the secondary side coil 2. The charger 3 comprises a first induction core 6 located in the primary side coil 7. The telephone 1 comprises a second induction core 9 located in the secondary side coil 2. Because of the spacing 5, the induction cores 6, 9 are spaced from each other. Various problems exist with the prior art system shown in FIG. 1. Both the portable telephone 1 and the charger 3 need to include a separate core 6, 9 made of magnetic material, such as metal. The weight and the size of the portable telephone 1 and the charger 3 is increased because each of these components require a separate induction core. Since the primary side coil and the secondary side coil are separate from each other, even a small deviation in the relative position between the two coils can exert an influence on charging efficiency. In the event a magnetic item, such as a coin or an accessory article, is accidentally held or located in the receiving area 4 of the charger 3, heat can be generated in the magnetic item which can present a fire concern. The housing of the charger 3 has a receiving area 4 for receiving a portion of the portable telephone. The receiving area is sized and shaped for a specific size and shape of portable telephone. Therefore, the charger 3 is not adapted to allow a plurality of different sizes and shapes of portable telephones or other portable electronic devices, to be used with the charger.
There is a desire to allow induction charging of a battery in a portable electronic device without increasing the weight and size of the portable electronic device by having to include an induction core in the device. There is also a desire to increase charging efficiency in induction charging equipment by allowing larger deviations in relative positioning between coils in a charger and the portable electronic device. There is also a desire to reduce the risk of generating heat in items accidentally located near the charger. There is also a desire to provide a charger which is adapted to accommodate different geometries, shapes or sizes of portable electronic devices. There is a desire to provide a portable charging device which can be used without a real time connection with an electrical outlet or main. There is also a desire to provide an improved charging system which is readily adaptable to different charging configurations. There is also a desire to provide a portable electronic device having an induction charging loop which can be used for at least one other function, such as a structural support loop for supporting the electronic device in a hanging configuration, or such as being housed in conjunction with a signal indicator adapted to visually signal at least one characteristic of the portable electronic device.